add: added libx11 warning on dependencies needed to use gapcast

Author: ANDRVV

README.md

@@ -175,7 +175,7 @@ go build -buildvcs=false
 <h1 align="center">📚Dependencies</h1>
 
 > [!CAUTION]
-> You must install ```libpcap```, ```apache2```, ```iptables```, ```hostapd```, ```dnsmasq```, ```aircrack-ng```, ```php```, if you'd use **gapcast**!
+> You must install ```libpcap```, ```libx11```, ```apache2```, ```iptables```, ```hostapd```, ```dnsmasq```, ```aircrack-ng```, ```php```, if you'd use **gapcast**!
 
 <h1 align="center">🚀Upcoming features</h1>
 <ul>